Barcelona's W Hotel is perched on an artificial island at the southernmost tip of the city's beach, which means there are sea views from every room. The soaring, sail-shaped edifice by Catalan architect Ricardo Bofill, has the feel of a berthed ship as much as a hotel. For the full effect, book the W's three-bedroom Extreme Wow Suite, which has a 635-square-foot terrace (complete with whirlpool tub) jutting out over the Mediterranean and floor-to-ceiling windows shielding a 360-degree city and sea outlook.

WOW Suite Bedroom -- Courtesy of W Hotels

Duquesa de Cardona Terrace -- Courtesy of Duquesa de Cardona

The Duquesa de Cardona boutique hotel sits on the edge of the Barri Gòtic, Barcelona's character-laden old town. The hotel faces Port Vell marina, a large community of boat dwellers that looks particularly beguiling at night when many of the boats' masts are illuminated by fairy lights. The 40-room hotel has 14 deluxe rooms with balconies overlooking the water. The classic decor, with damask textiles and faux regency details, harmonizes with the hotel's mid-19th-century architecture.

Hotel Arts Exterior -- Courtesy of Hotel Arts

Though most rooms at the Hotel Arts, a 44-story blue glass and steel tower, offer sea views, the 30th floor Arts Suite by Barcelonese architect Josep Juanpere is the one to book. The contemporary furnishings are luxurious, such as a huge, cushion-strewn modular sofa, with a neutral palate so as not to detract from the outlook over the Mediterranean Sea and Port Olímpic marina. This room-with-a-killer-view is part of an ongoing refurb of the hotel -- this April saw a renewel of the Club Level lounge -- which originally opened for the city's 1992 Olympic Games.